Analysing the Rockmass Permeation of a Low-medium Radioactive Waste Disposal Field

The fractures distribution and fracture rock mass permeation research is the premise condition that to study groundwater movement and pollutant migration in fracture rock mass in bed rock area, which includes the dominance orientation of fracture that groundwater fluxes in it, the brisk zone distribution of fracture water and the permeability calculation of rock mass. This paper mainly analyzes the fracture distribution and the dominance orientation of fracture and the permeability of a low-medium radioactive waste disposal field based on its rich geologic record. The following results are found through Statistical analysis and comparison calculation.The active zone of fractural water in bed rock is an active channel of active nucleus migration. Tthe headrace fracture of disposition have a dominant orientation. The penetrating coefficient tensor in bed rock fracture is also calculated.     

ANALYTICAL SOLUTION OF RING SHELL LINING WITH ANNULARLY VERTICAL WALLS MADE CONTACT WITH SURROUNDING ROCK

In this paper,the ring shell lining with annularly verticalwalls made contact with the surrounding rock is considered as a combinationstructure formed of ring shell,inner and outer annular barrels on elastic fo-undation.The complex equation and its solutions of ring shell under deadload of lining and vertical and horizontal surrounding rock pressures are de-rived by the method of complex function.The governing equation and itssolution of the barrels on elastic foundation are also derived by theory ofcylindrical shell.And then,the ring shell lining is assembled by the subst-ructures by means of compatibility conditions of internal forces and defor-mations between them.In the paper,all formulas for the practical computa-tion in engineering are derived,the numerical examples are given and theeffects of the parameters of the lining on the work behaviours of lining alsoare discussed preliminarily     

Numerical Analysis on Stability of Rock in Sijiaotian Tunnel

The Sijiaotian Tunnel in Yunnan Dabao Highway lies in the narrow defile landscape,and the engineering geology condition is complex,with plenty of cienega.According to the actual situation of the Sijiaotian Tunnel Project in Yunnan Dabao Highway,the stability of the surrounding rock mass is studied by using a 3-D non-linear FEM.The Drucker-Prager criterion is chosen as the failure criterion of the rock.The relatively dangerous zone and the monitoring points in the tunnel are determined.The numerical results show that the Sijiaotian Tunnel is relatively stable.The conclusion has some significance for guiding the construction of similar projects.     

Stability analysis on shallow tunnel with floor lift under inclined ground by upper bound method

采用极限分析上限法,基于内外能耗守恒原理,通过构建考虑隧底隆起的斜坡地段浅埋隧道破坏模式,推导出围岩压力的计算式,并通过典型算例重点分析了典型因素对隧道围岩稳定性的影响。研究结果表明：基于泰沙基极限平衡法进行隧道围岩支护设计较为保守,不考虑隧底隆起的极限分析方法次之考虑隧底隆起极限分析方法的风险最大;斜坡地表倾角增大对浅埋隧道稳定性有着不可忽视的不利影响;围岩压力随岩土侧压力系数减小、埋深增大、断面尺寸加大而增大;岩土黏聚力增大、内摩擦角增大对提高浅埋隧道围岩稳定性有积极作用。     

STRENGTH PROPERTIES OF ROCK MASS WITH BIDIRECTIONAL INTERMITTENT CROSS JOINTS

In this paper,the strength properties of rock mass withrows of intermittent bidirectional cross joints by simulating models arediscussed.Work has been done on finding the failure mechanism of therock mass as well as the influence of joint direction and lateral pressureon tne strength of the rock mass.At the end of the paper,model testresults ahd FEM analyses are presented and strength criteria for thiskind of rock mass are proposed.     

NONLINEAR ELASTIC-DAMAGE CONSTITUTIVE EQUATION OF BRITTLE ROCK AND EXPERIMENAAL VERIFICATION

on the basis of the experimental studies of mechanical properties in brittle rock,the generalized elastic modulus,generalized elastic Poisson ratio,irreversible deformation Poisson ratio and damage deformation characteristic arediscussed.And then,a new damage variable is defined.A new nonlinear elastic-damage constitutive equation is built and the damage evolution equation is proposed.The nonlinear elastic-damage constitutive equation is verified in the uniaxialcompression test of quartz sandstone in Chongqing.The results show that reasonableagreement exists between the theoretical analysis and the experimental data.     

BP神经网络在隧道岩爆预测中的应用

西南某水电站拟修建四条引水隧洞以及两条平行交通隧道,但工程区一般埋深1000-2000 m,最大埋深2525m,地处高应力区,目前已开挖的2000m洞段中均发现轻微至中等的岩爆现象。因此,在深埋、长大的隧道以后开挖过程中岩爆烈度如何显得十分敏感,利用BP人工神经网络,建立了以强度脆性系数、应力系数等8指标为要素的岩爆预测模型,对12200m未开挖的辅助洞段进行了预报,结果表明,该方法的预报效果较好。与地质分析判断相吻合,可用于进一步指导实践。     

重庆市某危岩治理研究浅析

危岩治理应在充分调查分析其发育的地质环境条件基础上,有针对性地采取各种治理措施,确保危岩的稳定性,同时要加强排水和监测工作。根据对重庆市某危岩特定地质环境条件的分析,采取了清除、支撑、排水、充填、灌浆等措施成功地进行了危岩治理。     

不同碎石含量及直径对土壤水分入渗过程的影响

由于成土原因或人类活动,一些土壤中含有不同含量及大小的碎石。碎石的存在改变了土壤的某些物理特性,入渗过程也因此受到影响。本研究采用定水头入渗试验装置,对7种不同碎石含量(0%,10%,20%,30%,40%,50%,60%)及4种不同碎石直径(0.2~0.5cm,0.5~1.0 cm,1.0~3.0 cm,3.0~4.0 cm)的土壤水分入渗过程进行室内研究,旨在分析碎石含量及直径对土壤入渗过程的影响及其原因,为土石混合介质的研究提供一些理论基础。